Journal of Entomology and Zoology Studies 2019; 7(2): 158-167

E-ISSN: 2320-7078 P-ISSN: 2349-6800 First report on development of sustainable JEZS 2019; 7(2): 158-167 © 2019 JEZS management strategy against Received: 11-01-2019 Accepted: 13-02-2019 nigronervosa coq. vector of banana bunchy top

Nilakshi Kakati virus disease, its seasonal variation and effect on Department of Plant Pathology, Assam Agricultural University, yield of banana in Jorhat district of Assam– A Jorhat, Assam, India north eastern state of India PD Nath Department of Plant Pathology, Assam Agricultural University, Jorhat, Assam, India Nilakshi Kakati and PD Nath

Abstract Field experiments were conducted during 2013-15 in experimental plots of Assam Agricultural University, Jorhat, Assam to evolve a suitable management strategy against vector of disease. Virus free planting material cv. Grand Naine (tissue cultured) along with different pesticide combinations were used to reduced vector population and disease incidence

in the field. Banana plants treated with foliar spraying of Imidacloprid @ 0.1% at 60, 90, 120 and 150

days after planting showed no disease incidence (0.00%), zero vector population count in all the two cropping seasons. Insect vector population was recorded in the range of 0.00 to 10.67, average 3.28 (2013-14), 0.00 to 9.33, average 2.67(2014-15) and 0.00 to 10.75, average 3.39 (pooled data).Whereas in untreated control plots recorded the highest disease incidence 95.84 per cent corresponding with a highest vector population in the range of 0.00 to 110.55, average 24.86 (pooled data).

Keywords: Pentalonia nigronervosa, Banana Bunchy Top Virus, Banana Bunchy Top disease, Imidacloprid, Azadirachtin, Verticillium lecanii

Introduction Assam along with other seven states of North East region of India is one of the micro-centre of evolution of wild bananas. Though India is the largest producer of bananas and plantains with an annual production of 29.78 million tones and productivity of 37.90 Mt/ha (NHB, 2014) [34] from an area of 0.748 million ha and accounts for 29 per cent of the world’s production still th Assam ranks 9 position in terms of production amongst the twelve major banana growing states of India with an annual production of 0.835 million tonnes and productivity of 15.20 t/ha from an area of 0.054 million ha (NRCB, 2012) [35]. This lower in production is due to various natural calamities, but diseases in particular, viral diseases constitute a major setback to this crop. Among viral infections, Banana bunchy top disease (BBTD) caused by a multi component single stranded DNA virus Banana bunchy top virus (BBTV) belongs to the genus [21] Babuvirus and family Nanoviridae (Harding et al., 1991) is the most serious and devastating disease of Banana ( spp.) which alone can cause yield losses up to 100% (FAOSTAT, 2009) [15]. BBTV is primarily transmitted by planting materials and secondly by an insect vector, banana which is widely distributed throughout tropical and subtropical areas of the world (Magee, 1940 and Foottit et al., 2010) [27, 16]. The banana aphid, Pentalonia

nigronervosa Coquerel (: ) is the only known vector of BBTV, transmitting the virus in a persistently circulative, nonpropagative manner (Magee, 1927 and Thomas and Dietzen, 1991) [26, 46]. Infective may transmit the virus in 15-20 hours or more of feeding on healthy plant but not by feeding for shorter period. Aphids feeding for a period of 2-96 hours on diseased plants increase their transmitting ability from 20-100 per cent [45] Correspondence (Sun, 1961) . The transmission of the virus by aphids is confined to short distance and the Nilakshi Kakati mean distance of new infections from their source of inoculums in an established plantation Department of Plant Pathology, was estimated at 17.2m (Allen, 1987) [3]. Viral diseases had been considered practically Assam Agricultural University, incurable and the first aim in managing these kinds of diseases was to reduce or eliminate Jorhat, Assam, India virus spread within the field. This approach would reduce disease incidence and yield loss. In ~ 158 ~ Journal of Entomology and Zoology Studies practice this aim could be achieved only when resistant Materials and Methods varieties were grown. Unfortunately, there are no known The field investigations were carried out in the experimental commercial cultivars of banana that are immune to BBTV fields of Horticultural Experimental Farm, Assam (Ranasingh, 2007) [40]. In case of BBTD also, control of the Agricultural University (AAU), Jorhat during 2013-14 and spread of viral pathogens transmitted by insect vectors is 2014-15 for management of BBTD and its vector banana usually of greater concern to growers than control of the aphid. The experimental site was situated at 26o and 27oN vector itself, insecticides are often not considered to be the latitude, 94° and 95oE longitude at an altitude of 86.8 m above primary method of control for this insect-vectored viral mean sea level. The experimental site falls under the Upper disease. This is especially true for non-persistently transmitted Brahmaputra Valley Zone of Assam. Banana cultivar “Grand viruses, as brief probes are sufficient for vector inoculation of Naine” (Tissue cultured seedlings) was selected as virus free pathogen (Perring et al., 1999) [37]. However, because planting material for the experiments. BBTD susceptible acquisition and inoculation times are longer for persistently cultivar “Dwarf Cavendish” was planted as border crop transmitted viruses, insecticidal control of vectors has been a surrounding the whole experimental plot for natural infection. useful component of control measures for this group of Field experiment was laid out in a randomized block design viruses. To control the secondary infection of BBTV with 12 treatments viz., (1) Azadirachtin @ 0.075% + B. transmitted by its insect vector Pentalonia nigronervosa in bassiana @ 1x 108 cfu/ml, (2) Azadirachtin @ 0.075% + V. banana field there is a need to find out alternative agents that lecanii @ 1x 108 cfu/ml, (3) Imidacloprid @ 0.025% + B. are pest specific, non-toxic, biodegradable, safe to natural bassiana @ 1x 108 cfu/ml, (4) Imidacloprid @ 0.025% + V. enemies, less prone to resistance and less expensive. In the lecanii @ 1x 108 cfu/ml, (5) Dimethoate @ 0.5% + B. integrated pest management (IPM) schedule against the bassiana @ 1x 108 cfu/ml, (6) Dimethoate @ 0.5% + V. insect-vector, inclusion of neem based formulations as well as lecanii @ 1x 108 cfu/ml, (7) Azadirachtin @ 0.3%, (8) biocontrol agents (BCAs) like entomopathogenic fungi has Imidacloprid @ 0.1%, (9) Dimethoate @ 0.2%, (10) B. been adopted globally (Alves and Lecuona, 1998; bassiana @ 1x 108 cfu/ml, (11) V. lecanii @ 1x 108 cfu/ml and Ramarethinam et al., 2004) [5, 39]. A lot of examples exist (12) Control in three replications. The treatments were where application of different selective chemical insecticides imposed on 60, 90, 120 and 150 days after planting (DAP). and fungi when used in combination provide satisfactory The recommended dose of pesticides were used for the control against many agricultural insect pests (Serebrove et experiments (Azadirachtin (0.15%) @ 3ml/l, Imidacloprid al., 2005; Purwar and Sachen, 2006) [43, 38]. But field 17.8% SL @ 1ml/l, Dimethoate 30EC (0.06%) @ 2ml/l and application of such fungi cannot give satisfactory results as BCAs (1x108 cfu/ml) @600-700 l/ha). Insect vectors were pesticides due to many abiotic and biotic factors. The use of estimated by direct count method. The population of the fungal biocontrol agents in IPM cannot be ignored. On the vector, banana aphid was counted at 15 days interval after other hand, the use of non selective or incompatible chemical planting up to harvesting of the crop from the all four plants pesticides may possibly have the potential to hinder the of each plot and the average vector population was estimated. vegetative growth and development of fungi adversely Natural incidence of BBTD was recorded by both Visual and affecting the IPM (Duarte et al., 1992 and Malo, 1993) [13, 29]. PCR detection at 3rd month (90 DAP), 7th month (210 DAP) For this reason, an understanding about the adverse effects of and 11th month (330 DAP) after planting. Each plant was different insecticides on entomopathogenic fungi is necessary. regularly inspected for the first appearance BBTD incidence. A number of experiments have been done to evaluate the It was calculated by counting number of plants infected and deleterious effects of chemical insecticides on different total number of plants in a plot. developmental stages of fungi (Alizadeh et al., 2007) [4]. The effect of these products may vary in different species and strains of fungi (Anderson et al., 1989) [6]. The results from such experimental work would direct the farmers to choose a more compatible pesticides and the adverse effects of the The yield of banana was recorded per plant and expressed in injudicious use of insecticides can be minimized (Butt et al., the bunch weight (Kg/Plant). The data from field observations [9, 24] 2001 and Inglis et al., 2001) . Therefore, there is a need were analysed by using randomized block design described by to manipulate the inhibitory effects of different insecticides on Panse and Sukhatme (1978) [36]. Effect of different weather the mycelial growth and sporulation of isolates of different parameters on vector population and disease incidence as well BCAs, as well as, to check the compatibility of these as effect BBTD and banana aphid population on yield of chemicals with these BCAs. Hence, an in vitro compatibility banana was also calculated by using simple correlation analysis of three entomopathogenic fungi viz., Beauveria coefficient formula and multiple linear regression equation. bassiana, Metarhizium anisopliae, Verticillium lecani with the chemical pesticides generally used in banana production Results and discussion system in Assam in three different concentrations, i.e., The effect of different treatments in the field during the two recommended dose (RD) (lethal), half of the recommended cropping seasons on population growth of Banana aphid, dose (½ RD) (sub lethal) and one fourth of the recommended BBTD incidence were presented in Fig. 1. From the pooled dose (¼ RD) (sub-sub lethal) was also conducted before data analysis of both the cropping season (2013-15), it was application in main banana field and finally best two evident that there was no BBTD incidence (0.00%) in the treatment combinations obtained were used further for treatment T8 where Imidacloprid was applied @ 0.1% which conducting field experiments (Kakati et al., 2018) [25]. Taking was followed by lowest incidence of 12.50 per cent (T7 these background into account a field experiment was =Azadirachtin @ 0.3% and T9 =Dimethoate @ 0.2%) and conducted to develop a suitable management strategy against 20.83 per cent in the treatment T4 where Imidacloprid was Banana bunchy top disease and its aphid vector in the banana applied @ 0.025% + V. lecanii @ 1x 108 cfu/ml. The crop field. treatments T7 and T9 were found statistically at par. While, the ~ 159 ~ Journal of Entomology and Zoology Studies highest BBTD incidence of 95.84 per cent was recorded in the (-) 0.693 and (-) 0.639, respectively. It was also revealed that control plots (T12). The highest per cent reduction in BBTD there was no banana aphids up to 165 DAP. Initial population incidence over control (T12) was recorded 100.00 in the of banana aphid was obtained from 180 DAP. There was no treatment T8 followed by 86.96 (T7 and T9) and 78.27(T4). insect vector population in the treatment T8 during the entire The results of correlation analysis(Table not presented) of cropping seasons (2013-15) followed by lowest population BBTD incidence and weather parameters during the two recorded in T9 and T7 ranging from 0.00 to 10.92, average cropping seasons showed that out of seven weather 3.04 and 0.00 to 10.75, average 3.39, respectively. Highest parameters only relative humidity (morning) (2014-15) and banana aphid population was recorded in the control (T12) in bright sun shine hour (BSSH) (2014-15) showed significant the range of 0.00 to 110.55, average 24.86. It was found that negative correlation with BBTD incidence which means in all the treatments the banana aphid population starts increase in relative humidity (morning) (2014-15) and BSSH increasing gradually after 180 DAP (6th month after planting), (2014-15) there was decrease in BBTD incidence during the attaining a peak at 195 DAP and starts decreasing gradually second cropping season (2014-15) whereas BBTD incidence from 210 DAP (7th month after planting) with complete with other weather parameters during the two cropping disappearance after 285 DAP. There was no banana aphid seasons showed non-significant correlation. The correlation population was found at 300, 315 and 330 DAP (11th month coefficients of BBTD incidence with relative humidity after planting). (morning) and BSSH during the second cropping season were

Fig 1: Bbtv Disease Incidence And Banana Aphid Population At 3rd, 7th And 11th Map (Months After Planting) (2013-15)

The results of correlation analysis of banana aphid population temperature (2014-15), minimum temperature (2013-14), and weather parameters of the two cropping seasons revealed minimum temperature (2014-15) and relative humidity that out of seven weather parameters only temperature (2013- (evening) (2014-15) were (-)0.626), (-)0.621, (-) 0.603), (-) 15) and relative humidity (evening) (2014-15) showed 0.647) and (-)0.582, respectively. The above results support significant (negative) correlation which means increase in the earlier findings of Young and Wright (2005) [51] that there temperature and relative humidity (evening) for the respective was no distinct or consistent pattern in seasonal distribution of cropping seasons there was a decrease in vector population in banana aphid population in Hawaii field condition. Similarly, the field. The correlation coefficients of banana aphid the results of correlation coefficient of banana aphid population with maximum temperature (2013-14), maximum population and BBTD incidence when analysed with different ~ 160 ~ Journal of Entomology and Zoology Studies weather parameters during the two cropping seasons (2013-14 all the cropping seasons. The highest banana aphid numbers and 2014-15) showed that no direct and significant correlation were recorded in the period 180-210 DAP (January and can be made between recorded aphid numbers and disease February) which corresponds to the dry and winter season in incidence. Jorhat, Assam. These findings were confirmatory to the It was evident from the pooled data analysis of the two earlier reports that in India, banana aphid population cropping season (2013-15) that banana aphid population increased in winter in plain areas, whereas in hill areas showed extreme seasonal fluctuation throughout the cropping population increased in summer (Anon, 2012) [7]. This period seasons with increase in population during the winter in field. is characterized by maximum temperatures (23.8 to 26 °C), These fluctuations in aphid numbers in field condition minimum temperatures (10.1-12.4 °C), relative humidity throughout the year were significantly influenced by the morning (88-95%), relative humidity evening (55-73%), prevailing high temperature and relative humidity (evening). BBSH (136.4 to 199.6 hrs.), rainfall (4.3 to 36.1mm) in The banana aphid population was also negatively influenced addition to the lowest number of rainy days only 1 to 3. The by rainfall and number of rainy days during the two cropping present findings were in concurrence with earlier reports of seasons but it was not significant. In all the treatments there seasonal distribution and correlation of banana aphid were no banana aphid populations recorded up to 165 DAP. population with weather parameters and BBTD incidence Population starts increasing gradually after 180 DAP, (Agarwala and Bhattacharya, 1994; Young and Wright, 2005; attaining a peak at 195 DAP and starts decreasing gradually Robson et al., 2006 and Niyongere, 2012) [1, 51, 41, 33]. from 210 DAP with complete disappearance after 285 DAP in

From the regression analysis following regression equations of weather parameters and disease incidence could be deduced: For First cropping season (2013-14): Y = 192.614 – 1.530X1+ 2.659X2 - 0.040X3 + 1.067X4 +0.570X5 -2.577X6 -0.409X7 R2 = 0.531 For Second cropping season (2014-15): Y = 292.679 + 2.687X1 - 3.625X2 + 0.102X3 - 1.060X4 – 3.205 X5 + 0.330X6 -0.153X7 R2 =0.875, Where, Y=BBTD incidence (percentage), X1= Maximum Temperature (°C), X2= Minimum Temperature (°C), X3= Rainfall (mm), X4 =Rainy days(nos.), X5 =Relative Humidity(Morning) (percentage), X6 =Relative Humidity(Evening) (percentage), X7 =BSSH(hrs.), R2=Coefficient of determination.

The result of the regression analysis of different weather humidity (evening) and BSSH were 0.236, 0.312, 1.058 and parameters against BBTD incidence showed that the there 0.584 per cent, respectively. Whereas, BBTD incidence was were no significant effects of weather parameters on BBTD positively influenced by minimum temperature, rainy days incidence during the two cropping seasons (2013-14 and and relative humidity (morning) which means for 1% increase 2014-15). During the first cropping season (2013-14), BBTD in the BBTD incidence the contribution of minimum incidence was negatively influenced by maximum temperature, rainy days and relative humidity (morning) were temperature, rainfall, relative humidity (evening) and BSSH 0.725, 0.327 and 0.069 per cent, respectively during the first which means for 1% decrease in the BBTD incidence, the cropping season. contribution of maximum temperature, rainfall, relative

Fig 2: Normal Probability Curve Showing Effect of Weather Parameters on Bbtd Incidence During Different Cropping Seasons (2013-14 And 2014-15) ~ 161 ~ Journal of Entomology and Zoology Studies

During the second cropping season (2014-15), it was found the BBTD incidence the contribution of maximum that BBTD incidence was negatively influenced by minimum temperature, rainfall and relative humidity(evening) were temperature, rainy days, relative humidity (morning) and 0.664, 1.162 and 0.209 per cent, respectively. Maximum BSSH which means for 1% decrease in the BBTD incidence contribution to the BBTD incidence was contributed by the contribution of minimum temperature, rainy days, relative minimum temperature followed by rainfall in the second year humidity (morning) and BSSH were 1.649, 0.614, 0.444 and cropping season (2014-15) (Figure 2).These findings were in 0.569 per cent, respectively. Whereas, BBTD incidence was concurrence with those reported earlier by Niyongere (2012) positively influenced by maximum temperature, rainfall, [33]. relative humidity (evening) which means for 1% increase in

The regression equations of weather parameters and banana aphid population could be deduced as: For First cropping season (2013-14): Y = 300.816-0.921X1-1.960X2-0.001X3+0.729X4-3.129X5+0.763X6+0.009X7 R2 = 0.954 For Second cropping season (2014-15): Y = 108.586+0.689X1-0.887X2-0.060X3 +0.698X4 – 0.180X5 - 0.858X6 -0.162X7 R2 =0.575 Where, Y=BBTD incidence (percentage), X1= Maximum Temperature (°C), X2= Minimum Temperature (°C), X3= Rainfall(mm), X4 =Rainy days(nos.), X5 =Relative Humidity(Morning) (percentage), X6 =Relative 2 Humidity(Evening)(percentage), X7 =BSSH(hrs.), R =Coefficient of determination.

The result of the regression analysis of different weather nonsignificant. During the second cropping season (2014-15), parameters against banana aphid population showed that the it was found that banana aphid population was negatively there were no significant effects of weather parameters on influenced by minimum temperature, rainfall, relative banana aphid population during the two cropping seasons humidity(morning), relative humidity(evening) and BSSH (2013-14 and 2014-15) except relative humidity (morning) which means for 1% decrease in the banana aphid population during the first cropping season (2013-14). During the first the contribution of minimum temperature, cropping season (2013-14), banana aphid population was rainfall, relative humidity (morning), relative humidity negatively influenced by maximum temperature, minimum (evening) and BSSH were 0.482, 0.818, 0.030, 0.649 and temperature, rainfall and relative humidity (morning) 0.721 per cent, respectively. Whereas, banana aphid (significant) which means for 1% decrease in the banana population was positively influenced by maximum aphid population, the contribution of maximum temperature, temperature and rainy days which means for 1% increase in minimum temperature, rainfall and relative humidity the banana aphid population the contribution of maximum (morning) were 0.327, 1.232, 0.024 and 0.871 per cent, temperature and rainy days were 0.203 and 0.483 per cent, respectively. Whereas, banana aphid population was respectively. Maximum contribution to the banana aphid positively influenced by rainy days and relative humidity population was contributed by minimum temperature (evening) and BSSH which means for 1% increase in the followed by relative humidity (morning) in the first year BBTD incidence the contribution of rainy days and relative cropping season (2013-14) (Fig. 3). These findings were in humidity(evening) and BSSH were 0.514, 0.722 and 0.029 concurrence with those reported earlier by Niyongere (2012) per cent, respectively which very negligible and [33].

Fig 3: Normal Probability Curve Showing Effect of Weather Parameters on Banana Aphid Population During Different Cropping Seasons (2013-14 And 2014-15)

~ 162 ~ Journal of Entomology and Zoology Studies

Yield of banana Imidacloprid was reported earlier by several researchers on The effects of different treatments in the field during the two different viral diseases. For example, Potato leaf roll virus cropping seasons (pooled data, 2013-15) on yield of banana (PLRV) by Myzus persicae (Boiteau and Singh, 1999; Mowry were presented in Figure 4. It was evident from the data that and Ophus, 2002; Mowry, 2005) [8, 31, 30], Beet mild yellowing the banana yield was significantly increases as the BBTV virus (BMYV) in sugar beets (Dewar et al., 1992) [11], Barley disease incidence and banana aphid population decreases in yellow dwarf virus (BYDV) in small grains (Gourmet et al., all the cropping seasons. The pooled data analysis of the first 1994 and Gray et al., 1996) [19, 20] and Bean leaf roll virus and second year cropping seasons (2013-15) revealed that, the (BLBLRV), Faba bean necrotic yellows virus (FBNBNYV), highest banana yield was recorded 43.55 kg/plant in the and Soybean dwarf virus (SbDV) in faba bean and lentil [28] treatment T8 where Imidacloprid was applied @ 0.1% (Makkouk and Kumari, 2001) . This holds true in case of followed by 36.54, 36.07 and 35.50 kg/plant in the treatments the present field experiment of BBTD management. From T9 (Dimethoate @ 0.2%), T7(Azadirachtin @ 0.3%) and pooled data (2013-15), it was found that the botanical 8 T4(Imidacloprid was applied @ 0.025% + V. lecanii @ 1x 10 pesticide, Azadirachtin @ 0.3% at 60, 90, 120 and 150 DAP cfu/ml), respectively. However, the treatments T9 and T7 were (T7) also showed promising results of lower BBTD incidence found to be statistically at par. The lowest yield of 0.88 (12.50%) and 0.00 to 10.75, average 3.39 banana aphid kg/plant was recorded in the control (T12). The overall population with 36.07 kg/plant banana yield. These results variation in yield in all the treated plots ranged from of 0.88 were in confirmatory to the earlier works conducted by to 43.55 kg/plant. The increase in banana yield over control researchers on management of Pentalonia nigronervosa f. recorded a maximum of 97.98 per cent in the treatment T8 caladii Van der Goot transmitting Katte disease in cardamom followed by 97.59, 97.56 and 97.52 per cent in the treatments through application of neem formulations which significantly T9, T7 and T4, respectively. The results of field experiments affected the settling and colonization behaviour and presented in the during the different cropping seasons showed multiplication of aphids in cardamom (Venugopal, 1999 and [48, 17] that both chemical as well as botanical pesticide had Gahukar, 2011) . However, the control treatment T12 significant effect on BBTD incidence, banana aphid recorded highest BBTD incidence of 100.00 per cent (2013- population and yield of banana plants. The most promising 14), 91.67 per cent (2014-15), 95.84 per cent (pooled, 2013- treatment T8 (Imidacloprid @ 0.1% at 60, 90, 120 and 150 15) and with the lowest yield of banana viz., 0.83 kg/plant DAP) recorded 0.00 per cent incidence of BBTD and zero (2013-14), 0.92 kg/plant (2014-15), 0.88 kg/plant (pooled, insect vector population in all seasons with highest 42.67 2013-15).These results were in conformity with those findings kg/plant (2013-14) and 44.42 kg/plant (2014-15) yield of reported earlier that because of high transmission efficiency banana. Similar results found in pooled data (2013-15) with of banana aphid, the disease incidence can increase rapidly 0.00 per cent BBTD incidence, zero insect vector population without control of aphid populations in field (Hu et al., 1996 and highest banana yield 43.55 kg/plant. These results were in and Smith et al.,1998) [23, 44]. Dale, 1987 [10] and Hooks et al., accordance with that of managing BBTD by controlling 2008 [22] reported that the BBTD incidence within the field banana aphid using Imidacloprid as foliar application under trial increased around 12 per cent per year resulting onto a field conditions in Hawaii as reported by Wright et al. (2007) gradual decrease in banana yields. They explained that the [50]. Imidacloprid is a neonicotinoid insecticide which lower average of bunch weight of BBTV infected banana interrupts the binding of nicotinergic acetylcholine in post- plants might be due to the low photosynthesis rate of chlorotic synaptic receptors of (Romoser and Stoffolano, 1998) leaves of infected plants which affecting the banana [42]. Effective control of the spread of viral pathogens production. transmitted persistently by their insect vectors by using

Fig 4: Effect of Different Treatments on Bbtd Incidence, Banana Aphid Population and Yield of Banana (Pooled Data, 2013-15)

~ 163 ~ Journal of Entomology and Zoology Studies

The correlation analysis of BBTD incidence and banana aphid population there was increase in BBTD incidence in all the population with yield of banana plants revealed that banana seasons. The correlation coefficients of banana aphid aphid population and BBTD incidence were positively population and BBTD incidence were 0.905, 0.980 and 0.967 correlated and showed highly significant relation between during the first cropping season (2013-14), second cropping them in all the cropping seasons (2013-14, 2014-15 and season (2014-15) and the pooled data, 2013-15, respectively. pooled data, 2013-15), which means increase in banana aphid

Fig 5: Correlation between yield of banana and banana aphid population during different cropping seasons (pooled data, 2013-15)

Fig 6: Correlation between yield of banana and bbtd incidence during different cropping seasons (pooled data, 2013-15)

The correlation coefficient results showed that banana aphid Similarly, the results of correlation analysis showed highly population and yield of banana were highly significant and significant and negative correlation between BBTD incidence negatively correlated in all the cropping seasons, which and yield in all the cropping seasons, which means that with means that increase in banana aphid population there was increase in BBTD incidence there was decrease in yield of decrease in yield of banana in all the seasons. The correlation banana in all the cropping seasons. The correlation coefficients of banana aphid population and yield were (-) coefficients of BBTD incidence and yield were (-)0.959, (-) 0.860, (-) 0.947) and (-) 0.949 during the first cropping season 0.962 and (-)0.975 during the first cropping season (2013-14), (2013-14), second cropping season (2014-15) and the pooled the second cropping season (2014-15) and pooled data, 2013- data, 2013-15, respectively (Figure 5). 15, respectively (Figure 6).

~ 164 ~ Journal of Entomology and Zoology Studies

Fig 7: Normal probability curve showing effect of BBTD Incidence and Banana aphid population on Yield of banana during different cropping seasons (2013-14, 2014-15 and pooled data, 2013-15)

From the analysis of regression the following regression equations of banana aphid population, BBTD incidence and yield of banana could be deduced: 2 For first cropping season (2013-14): Y=44.072-0.468X1+0.069X2, R =0.920 2 For Second cropping season (2014-15): Y=46.897 - 0.460X1 - 0.166X2, R =0.927 For pooled data of first and second cropping season (2013-15): 2 Y=45.211-0.429X1 – 0.162X2, R =0.951 2 Where, Y=Yield (kg/plant), X1=BBTD incidence (percentage), X2=Banana aphid population (nos.) R =Coefficient of determination.

The results of the regression analysis of different cropping showed that the yield of banana was negatively influenced by seasons of banana showed that the yield of Banana was the BBTV disease incidence and vector population. It was negatively influenced by the BBTD incidence. For 1 per cent recorded that for 1per cent reduction in yield, the BBTD reduction in yield, the BBTD incidence contribution was (-) incidence contribution was (-) 0.872 per cent whereas, banana 0.996 per cent (highly significant) during the first cropping aphid population contribution was (-) 0.092 per cent but they season (2013-14). Though, banana aphid population were non-significant (2014-15).The regression analysis of contribution (0.04%) was found positive, it was very pooled data of the two cropping seasons (2013-15) also negligible and non-significant also (2013-14). The regression showed that the yield of Banana was negatively influenced by analysis of second cropping season (2014-15) of banana the BBTV disease incidence and vector population. It was ~ 165 ~ Journal of Entomology and Zoology Studies recorded that for 1 per cent reduction in yield, the BBTD Chrysomelidae): Effects of combinations of Beauveria incidence contribution was (-) 0.882 per cent (significant) bassiana withinsecticides. J. Econ. Entomol. 1989; whereas, banana aphid population contribution was 0.096 per 82(1):83-89. cent but it was non-significant (pooled data, 2013-15). 7. Anonymous. IPM schedule for banana pest. National Maximum contribution to the yield reduction was contributed Horticulture mission, Department of Agriculture and by BBTV disease incidence in the first cropping season Cooperation, Krishi Bhawan, New Delhi, 2012. (2013-14) (Figure 7). The above results were in concurrence 8. Boiteau G, Singh RP. Field assessment of imidacloprid to with those reported by Robson et al., 2006 [41] and Niyongere reduce the spread of PVYO and PLRV in potato. (2012) [33]. American Journal of Potato Research. 1999; 76:31-36. The findings of this research would be helpful for initiating 9. Butt TM, Jackson CW, Magan N. Fungal biological future strategies in disease diagnostics and resistant breeding. control agents: Progress, Problems and Potential. CABI The above research findings elucidate the importance of use International, Wallingford, Oxon, UK, 2001, 377-384. of disease free planting material and chemical control in 10. Dale JL. An economically important tropical plant virus effective management of the spread of viral pathogens disease. Adv. Virus Res. 1987; 33:301-325. transmitted persistently by their insect vectors. To the best of 11. Dewar AM, Read LA, Hallsworth PB, Smith HG. Effect our knowledge these findings are the first report from Assam. of imidacloprid on transmission of viruses by aphids in Field efficacy of biocontrol agents with chemical and sugar beet. In: Brighton Crop Protection Conference botanical pesticides used in banana production system are Pests and Diseases, Brighton, United Kingdom, 1992. important in developing strategies for the efficient utilization 12. Drew RA, Moisander JA, Smith MK. The transmission of of entomopathogens against insect vector in the integrated Banana bunchy top virus in micropropagated bananas. pest management of banana. Therefore an integrated approach Plant cell, tissue and organ culture. 1989; 16:187-193. such as use of certified disease free banana planting material 13. Duarte A, Menendez JM, Trigueiro N. Estudio preliminar (tissue cultured, Grand Naine) as well as field application of sobre la compatibilidad de Metarhizium anisopliae com chemical pesticides viz., Imidacloprid @ 0.1 per cent at 60, algunos plaguicidas quimicos. Revista Baracoa. 1992; 90, 120 and 150 DAP or botanical pesticides viz., 22:31-39. Azadirachtin @ 0.3% at 60, 90, 120 and 150 DAP would be 14. Elayabalan S, Kalaiponmani K, Subramaniam S, applicable in the farmer’s field for sustainable management of Selvarajan R, Panchanathan R, Muthuvelayoutham R et BBTD. In the present day context, due to the limited use of al. Development of Agrobacterium-mediated conventional chemical control, there is a need to develop eco- transformation of highly valued hill banana cultivar friendly strategies to combat the high incidence of BBTD and Virupakshi (AAB) for resistance to BBTV disease. its vector population. Hence, the strategies mentioned above World J Microbiol Biotechnol. 2013; 29(4):589-96. would play an important role in managing the BBTD in a 15. FAOSTAT. Food and agricultural commodities by sustainable manner. country. FAO, Rome. Availabe on-line [http: //www.faostat.fao.org/site/339/default.aspx]. 2009. Acknowledgement 16. Foottit RG, Maw HEL, Pike KS, Miller RH. The identity The authors thankful to the Head of Department of Plant of Pentalonia nigronervosa Coquerel and P. caladii van Pathology, Director of Research as well as Director of post der Goot (Hemiptera: Aphididae) based on molecular and graduate studies, Assam agricultural university, Jorhat, Assam morphometric analysis. Zootaxa. 2010; 2358:25-38. for providing the experimental site and related facilities 17. Gahukar RT. Use of indigenous plant products for during the course of these investigations. management of pests and diseases of spices and condiments: Indian perspective. Journal of Spices and References Aromatic Crops. 2011; 20(1):01-08. 1. Agarwala BK, Bhattacharya S. Anholocycly in tropical 18. Ganapathi TR, Shekhawat UKS, Hadapad AB. aphid’s population trends and influence of temperature on Transgenic banana plants expressing small interfering development, reproduction, and survival of three aphid RNAs targeted against viral replication initiation gene species (Homoptera: Aphidoidea). Phytophaga. 1994; display high-level resistance to banana bunchy top virus 6:17-27. infection. Journal of General Virology. 2012; 93:1804- 2. Akram M, Kumar R. Advances in diagnosis and 1813. management of Banana bunchy top disease. In: Insect 19. Gourmet C, Hewings AD, Kolb FL, Smyth CA. Effect of pest and disease management.Prasad, D.(Ed.) Daya imidacloprid on nonflight movement of Rhopalosiphum Publishing house, 2008, 529-544. padi and the subsequent spread of barley yellow dwarf 3. Allen RN. Further studies on epidemiological factors virus. Plant Disease. 1994; 78:1098-1101. influencing control of banana bunchy top disease and 20. Gray SM, Bergstrom GC, Vaughan R, Smith DM, Kalb evaluation of control measures by computer simulation. DW. Insecticidal control of cereal aphids and its impact Aus. J Agric. Res. 1987; 38:373-382. on the epidemiology of the barley yellow dwarf 4. Alizadeh A, Samih MA, Izadi H. Compatibility of luteoviruses. Crop Protection. 1996; 15:87-697. Verticillium lecani (Zimm.) with several pesticides. 21. Harding RM, Burns TM, Dale JL. Virus-like particles Commun. Agric. Appl. Biol. Sci. 2007; 72(4):1011-5. associated with banana bunchy top disease contain small 5. Alves SB and Lecuona RE. Epizootiologia aplicada ao single-stranded DNA. Journal of General Virology. 1991; controle microbiano de insetos, p. 97-170. In: Controle 72:225-230. microbiano de insetos S.B. Alves, Paulo, S. F. (Eds.). 22. Hooks CRR, Wright MG, Kabasawa DS, Manandhar R, 1998, 1163. Almeida RPP. Effect of Banana bunchy top virus 6. Anderson TE, Hajek AE, Roberts DW, Preisler K, infection on morphology and growth characteristics of Robertson JL. Colorado potato beetle (Coleoptera: banana. Annals of Applied Biology. 2008; 153:1-9.

~ 166 ~ Journal of Entomology and Zoology Studies

23. Hu JS, Wang M, Sether D, Xie W, Leonhardt KW. Use 39. Ramarethinam S, Marimuthu S, Murugesan V. Effect of of polymerase chain reaction (PCR) to study transmission Nimbicidine (0.03% Azadirachtin) on the major insect of Banana bunchy top by banana aphid (Pentalonia pest and their natural enemies of rice, Oryza sativa Linn. nigronervosa). Annals of Applied Biology. 1996; 128: in South India. Pestology. 2004; 28(7): 27-32. 55-64. 40. Ranasingh N. Field Diagnosis and Management of 24. Inglis GD, Goettel MS, Butt TM, Strasser H. Use of Banana bunchy top disease. Orissa Review. 2007, 78-80. hyphomycetous fungi for managing insect pests. In: 41. Robson JD, Wright MG, Almeida RPP. Within-plant Fungi as biocontrol agents progress, problems and spatial distribution and binomial sampling of Pentalonia potential. Butt, T. M., Jackson, C. and Magan, N. (Eds.) nigronervosa (Hemiptera: Aphididae) on banana. Journal CAB International, UK. 2001, 23-70. of Economic Entomology. 2006; 99:2185-2190. 25. Kakati N, Dutta P, Das P, Nath PD. Compatibility of 42. Romoser WS, Stoffolano JG. J. The Science of Entomopathogenous Fungi with Commonly used Entomology. Boston, WCB /McGraw-Hill, 1998. Insecticides for Management of Banana Aphid 43. Serebrov VV, Khodyrev VP, Gerber ON, Tsvetkova VP. transmitting Banana bunchy Top virus (BBTV) in Assam Per spectives of combined use of entomopathogenic fungi Banana Production System. Int. J. Curr. Microbiol. App. and chemical insecticides against Colorado Beetle Sci. 2018; 7(11):2507-2513. (Leptinotarsa decemlineata). Mikologiya I 26. Magee CJP. Investigation on the bunchy top disease of Fitopatologiya. 2005; 39(3):89-98. banana. Council for Scientific and Industrial Research, 44. Smith MC, Holt J, Kenyon L, Foot H. Quantitative Melbourne, Australia. 1927, 86. epidemiology of Banana Bunchy Top Virus Disease and 27. Magee CJP. Transmission studies on the Banana bunchy its control. Plant pathology. 1998; 47:177-187. top virus. The Journal of the Australian Institute of 45. Sun SK. Studies on the bunchy top disease of bananas. Agricultural Science. 1940; 6:18-109-110. Special Publication College of Agriculture, Taiwan 28. Makkouk KM, Kumari SG. Reduction of incidence of University. 1961; 10:82-109. three persistently transmitted aphid-borne viruses 46. Thomas JE, Dietzen RG. Purification, characterization affecting legume crops by seed-treatment with the and serological detection of virus like particles associated insecticide Imidacloprid (Gaucho®). Crop Protection. with Banana bunchy top disease in Australia. J. Gen. 2001; 20:433-437. Virol. 1991; 72:217-224. 29. Malo AR. Estudio sobre la compatibilidad del hongo 47. Thomas JE, Caruana MLI. Diseases caused by virus: Beauveria bassaina (Bals.) Vuill. conformulaciones Bunchy top. In: Diseases of banana, Abaca and Enset. comerciales de fungicidas e insecticidas. Revista Jones, D. R.(Ed.),CABI, Wallingford. 2000, 241-253. Colombiana de Entomologia. 1993; 19:151-158. 48. Venugopal MN. Characterization, early detection and 30. Mowry TM. Insecticidal reduction of Potato leafroll virus management of kokkekandu disease of cardamom. Final transmission by Myzus persicae. Annals of Applied Report of Ad-hoc Research Scheme, Indian Institute of Biology. 2005; 146:81-88. Spices Research, Calicut, 1999. 31. Mowry TM, Ophus JD. Effects of sub-lethal imidacloprid 49. Viljoen A. Protecting the African Banana (Musa spp.): on potato leafroll virus transmission by Myzus persicae. Prospects and Challenges. In: Acta Horticulturae 1:879. Entomologia Experimentalis et Applicata. 2002; Dubois,T., Hauser,S., Staver, C. and Coyne, D. (Eds). 103:249-255. International Conference on Banana and Plantain in 32. Muratori FB, Raymond JG, Russell HM. Ecological traits Africa: Harnessing International Partnerships to Increase of a new aphid parasitoid, Endaphis fugitiva (Diptera: Research Impact, Mombassa, Kenya, 2008, 305-313. Cecidomyiidae), and its potential for biological control of 50. Wright MG, Robson JD, Almeida PP. Effect of the banana aphid, Pentalonia nigronervosa (Hemiptera: imidacloprid foliar treatment and banana leaf age on Aphididae). Biological Control.2009; 50:185-193. Pentalonia nigronervosa (Hemiptera, Aphididae) 33. Niyongere C. Occurrence, characterization and screening survival. New Zealand Journal of Crop and Horticultural for resistance to Banana buncy top virus in Burundi, Science. 2007; 35:415-422. Democratic Republic of the Congo and Rwanda. PhD 51. Young CL, Wright MG. Seasonal and Spatial thesis, Jomo Kenyatta University of Agriculture and Distribution of Banana Aphid, Pentalonia nigronervosa Technology, Kenya, 2012. (Hemiptera: Aphididae), in Banana Plantations on Oahu. 34. NHB. National Horticultural Board. Indian Horticulture Proceedings of the Hawaiian Entomological Society. database – 2014[http://www.nhb.gov.in/].2014. 2005; 37:73-80. 35. NRCB. National Research Centre for Banana,Trichy, ICAR, India. Banana Scenario, 2012[http://www.nrcb.res.in/].2012. 36. Panse VG, Sukhatme PV. Statistical methods for agricultural workers. ICAR, New Delhi.1978, 145-146. 37. Perring TM, Gruenhagen NM, Farrar CA. Management of plant viral diseases through chemical control of insect vectors. Annual Review of Entomology.1999; 44:457- 481. 38. Purwar JP, Sachan GC. Synergistic effect of entomogenous fungi on some insecticides against Bihar hairy caterpillar Spilarctia oblique (Lepidoptera: Arctiidae). Microbiol. Res. 2006; 161(1):38-42.

~ 167 ~